"After a collaborative review with the Centers for Disease Control and Prevention of the recent cases and its potable water supply system, VA Pittsburgh has determined that an elevated concentration of the organism was present," the release states.

VA Pittsburgh staff referred all questions to its public-relations office, which did not immediately return calls seeking additional information.

Legionnaire's disease is caused by the baceterium Legionella, a form of pneumonia. An infection can occur when small droplets of water contaminated with Legionella is inhaled.

Early symptoms are a headache and high fever and chills two to 10 days after exposure. By the second or third day of illness, symptoms of pneumonia may arise including cough, chest pain and shortness of breath, VA Pittsburgh states.

VA Pittsburgh officials are working to eliminate Legionella from the water system. Currently, the medical facility is equipped with a copper-silver ionization system that is expected to reduce Legionalla in the water, but the news release says the system may not be working effectively. Officials have decided to use chlorination to disinfect the water system.

For years, Legionella in the water has been a recurring problem for veterans' hospital nationwide.

"Most people exposed to the bacteria do not become ill," the release states. "Elderly people, smokers and individuals with chronic lung disease or weakened immune systems are more vulnerable. The disease is not contagious and cannot be transmitted from one person to another."